Insertional tagging, cloning, and expression of the Toxoplasma gondii hypoxanthine-xanthine-guanine phosphoribosyltransferase gene. Use as a selectable marker for stable transformation

A nonhomologous integration vector was used to identify the Toxoplasma gondii hypoxanthine-xanthine-guanine phosphoribosyl transferase (HXGPRT) gene by insertional mutagenesis. Parasite mutants resistant to 6-thioxanthine arose at a frequency of approximately3 x 10(-7). Genomic DNA flanking the insertion sites was retrieved by marker rescue and used to identify molecular clones exhibiting unambiguous homology to H(X)GPRT genes from other species. Sequence analysis of vector/genome junction sites reveals that integration of the linearized vector occurred with minimal rearrangement of either vector or target sequences, although the addition of filler DNA and small duplications or deletions of genomic sequences at the transgene termini was observed. Two differentially spliced classes of cDNA clones were identified, both of which complement hpt and gpt mutations in Escherichia coli. Kinetic analysis of purified recombinant enzyme revealed no significant differences between the two isoforms. Internally deleted clones spanning the genomic locus were used to create "knock-out" parasites, which lack all detectable HXGPRT activity. Complete activity could be restored to these knock-out mutants by transient transformation with either genomic DNA or cDNA-derived minigenes encoding both enzyme isoforms. Stable HXGPRT+ transformants were isolated under selection with mycophenolic acid, demonstrating the feasibility of HXGPRT as both a positive and negative selectable marker for stable transformation of T. gondii.

Mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase and epidemiologic patterns of pyrimethamine-sulfadoxine use and resistance

To assess the relationship between mutations in Plasmodium falciparum dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) and clinical pyrimethamine-sulfadoxine resistance, polymerase chain reaction surveys and analyses for new mutations were conducted in four countries with increasing levels of pyrimethamine-sulfadoxine resistance: Mali, Kenya, Malawi, and Bolivia. Prevalence of mutations at DHFR codon 108 and a new mutation at DHPS 540 correlated with increased pyrimethamine-sulfadoxine resistance (P < .05). Mutations at DHFR 51, DHFR 59, and DHPS 437 correlated with resistance without achieving statistical significance. Mutations at DHFR 164 and DHPS 581 were common in Bolivia, where pyrimethamine-sulfadoxine resistance is widespread, but absent in African sites. Two new DHFR mutations, a point mutation at codon 50 and an insert at codon 30, were found only in Bolivia. DHFR and DHPS mutations occur in a progressive, stepwise fashion. Identification of specific sets of mutations causing in vivo drug failure may lead to the development of molecular surveillance methods for pyrimethamine-sulfadoxine resistance.

Fluoxetine in the treatment of premenstrual dysphoria. Canadian Fluoxetine/Premenstrual Dysphoria Collaborative Study Group

BACKGROUND

Premenstrual dysphoria shares certain features with depression and anxiety states, which have been linked to serotonergic dysregulation. We evaluated the efficacy and safety of fluoxetine (which selectively inhibits the reuptake of serotonin) in the treatment of premenstrual dysphoria.

METHODS

The trial consisted of a single-blind, placebo washout period lasting two menstrual cycles, followed by a randomized, double-blind, placebo-controlled trial of fluoxetine at a dose of either 20 mg or 60 mg per day or placebo for six menstrual cycles. Healthy women meeting criteria for what was then called late-luteal-phase dysphoric disorder were recruited at seven university-affiliated women's health clinics in Canada. The primary outcome measure consisted of visual-analogue scales for tension, irritability, and dysphoria during the late luteal phase of each cycle.

RESULTS

Of 405 women enrolled in the placebo washout period, 313 subsequently entered the randomized phase of the study, which lasted six menstrual cycles, and 180 completed it. Fluoxetine at a dose of 20 or 60 mg per day was significantly superior to placebo in reducing symptoms of tension, irritability, and dysphoria, as measured by the visual-analogue scales (P < 0.001). The women who received 60 mg of fluoxetine per day reported significantly more side effects than those who received 20 mg per day or placebo (P < 0.001).

CONCLUSIONS

Fluoxetine is useful in the treatment of premenstrual dysphoria. Treatment with fluoxetine at a dose of 20 mg per day reduces the potential for side effects while maximizing therapeutic efficacy.

True recurrence vs. new primary ipsilateral breast tumor relapse: an analysis of clinical and pathologic differences and their implications in natural history, prognoses, and therapeutic management

PURPOSE

The purpose of this study was to classify all ipsilateral breast tumor relapses (IBTR) in patients treated with conservative surgery and radiation therapy (CS+RT) as either new primary tumors (NP) or true local recurrences (TR) and to assess the prognostic and therapeutic implications of this classification.

METHODS AND MATERIALS

Of the 1152 patients who have been treated at Yale-New Haven Hospital before 1990, 136 patients have experienced IBTR as their primary site of failure. These relapses were classified as either NP or TR. Specifically, patients were classified as NP if the recurrence was distinctly different from the primary tumor with respect to the histologic subtype, the recurrence location was in a different location, or if the flow cytometry changed from aneuploid to diploid. This information was determined by a detailed review of each patient's hospital and/or radiotherapy record, mammograms, and pathologic reports.

RESULTS

As of 2/99, with a mean follow-up of 14. 2 years, the overall ipsilateral breast relapse-free rate for all 1152 patients was 86% at 10 years. Using the classification scheme outlined above, 60 patient relapses were classified as TR, 70 were classified as NP and 6 were unable to be classified. NP patients had a longer mean time to breast relapse than TR patients (7.3 years vs. 3.7 years, p < 0.0001) and were significantly younger than TR patients (48.9 years vs. 54.5 years, p < 0.01). Patients developed both TR and NP at similar rates until approximately 8 years, when TR rates stabilized but NP rates continued to rise. By 15 years following original diagnosis, the TR rate was 6.8% compared to 13.1% for NP. Of the patients who had been previously tested for BRCA1/2 mutations, 17% (8/52) had deleterious mutations. It is noteworthy that all patients with deleterious mutations had new primary IBTR, while patients without deleterious mutations had both TR and NP (p = 0.06). Ploidy was evenly distributed between TR and NP but NP had a significantly lower S phase fraction (NP 13.1 vs. TR 22.0, p < 0.05). The overall survival following breast relapse was 64% at 10 years and 49% at 15 years. With a mean follow-up of 10.4 years following breast relapse, patients with NP had better 10-year overall survival (TR 55% vs. NP 75%, p < 0.0001), distant disease-free survival (TR 41% vs. NP 85%, p < 0.0001), and cause-specific survival (TR 55% vs. NP 90%, p < 0.0001).

CONCLUSION

It appears that a significant portion of patients who experience ipsilateral breast tumor relapse following conservative surgery and radiation therapy have new primary tumors as opposed to true local recurrences. True recurrence and new primary tumor ipsilateral breast tumor relapses have different natural histories, different prognoses, and, in turn, different implications for therapeutic management.

Adenoid cystic carcinoma: a retrospective clinical review

Adenoid cystic carcinoma (ACC) are uncommon tumors, representing about 10% to 15% of head and neck tumors. We compare the survival and control rates at our institution with those reported in the literature, and examine putative predictors of outcome. All patients registered with the tumor registry as having had ACC were identified. Demographic and survival variables were retrieved from the database. Additionally, a chart review of all patients was done to obtain specific information. Minor gland tumors were staged using the American Joint Committee on Cancer's criteria for squamous cell carcinomas in identical sites. Histopathologic variables retrieved included grade of the tumor, margins, and perineural invasion. Treatment modalities, field sizes, and radiation doses were recorded in applicable cases. An effort to retrieve archival tumor specimens for immunohistochemical analysis was undertaken. A total of 69 patients were treated for ACC from 1955 to 1999. One patient, who presented with fatal brain metastasis, was excluded from further analysis. Of the remaining 68 patients, 30 were men and 38 were women. The average age at diagnosis was 52 years, and mean follow-up was 13.2 years. Mean survival was 7.7 years. Overall survival (OS) rates at 5, 10, and 15 years were 72%, 44%, and 34%, and cause-specific survival was 83%, 71%, and 55%, respectively. Recurrence-free survival rates were 65%, 52%, and 30% at 5, 10, and 15 years, with a total of 29 of 68 (43%) eventually suffering a recurrence. Overall survival was adversely affected by advancing T and AJCC stage. Higher tumor grades were also associated with decreased OS, although the numbers compared were small. Primaries of the nasosinal region fared poorly when compared with other locations. Total recurrence-free survival, local and distant recurrence rates were distinctly better in primaries of the oral cavity/oropharynx when compared with those in other locations. Reduced distant recurrence-free survival was significantly associated with increasing stage. No other variables were predictive for recurrence. Additionally, we found that nasosinal tumors were more likely to display higher stage at presentation, and were more often associated with perineural invasion. Also of interest was the association of perineural invasion with margin status, with 15 of 20 patients with positive margins displaying perineural invasion, while only 5 of 17 with negative margins showed nerve invasion (P = 0.02). On immunohistochemistry, 2 cases of the 29 (7%) tumor specimens found displayed HER-2/neu positivity. No correlation between clinical behavior and positive staining could be demonstrated. Our data concur with previous reports on ACC in terms of survival and recurrence statistics. Stage and site of primary were important determinants of outcome. Grade may still serve a role in decision making. We could not demonstrate any differences attributable to primary modality of therapy, perhaps due to the nonrandomization of patients into the various treatment tracks and the inclusion of palliative cases. Similarly, perineural invasion, radiation dose and field size, and HER-2/neu positivity did not prove to be important factors in our experience.

Uncommon high-risk lesions of the breast diagnosed at stereotactic core-needle biopsy: clinical importance

PURPOSE

To assess the outcome of papillary lesions, radial scars, or lobular carcinoma in situ (LCIS) diagnosed at stereotactic core-needle biopsy (SCNB).

MATERIALS AND METHODS

Retrospective review of 1,236 lesions sampled with SCNB yielded 22 papillary lesions, nine radial scars, and five LCIS lesions. Diffuse lesions such as papillomatosis, papillary ductal hyperplasia, papillary ductal carcinoma in situ (DCIS), and atypical lobular hyperplasia were not included. The mammographic findings, associated histologic features, and outcome were assessed for each case.

RESULTS

Sixteen papillary lesions were diagnosed as benign at SCNB. Of these, five were benign at excision, and 10 were unremarkable at mammographic follow-up. At excision of an unusual lesion containing a microscopic papillary lesion, DCIS was found. Three of four papillary lesions suspicious at SCNB proved to be papillary carcinomas; the fourth had no residual carcinoma at excision. Eight of nine radial scars were excised, which revealed atypical hyperplasia in four scars but no malignancies. One LCIS lesion was found at excision to contain DCIS.

CONCLUSION

Benign or malignant papillary lesions were accurately diagnosed with SCNB in the majority of cases. Cases diagnosed as suspicious for malignancy or with atypia or unusual associated histologic findings should be excised. No malignancies were found at excision of radial scars diagnosed at SCNB. Surgical removal of these lesions following SCNB may not be routinely necessary. DCIS was found in one lesion diagnosed as LCIS at SCNB, which suggests that removal of these lesions may be prudent.

Correlation of Doppler US tumor signals with neovascular morphologic features

Abnormal Doppler ultrasound signals were detected in 44 of 47 patients with primary malignant tumors of the liver, kidney, adrenal gland, or pancreas (94%). Two different signal types were noted: a high-velocity signal (n = 38) with Doppler shifts exceeding 3 kHz (at an insonating frequency of 3 MHz) and a very low-impedance signal (n = 9) demonstrating little systolic-diastolic variation. In three patients, both types were present. In 19 patients, histologic (n = 12) and/or angiographic (n = 16) correlation was available. Among 13 patients with angiographic studies and signals over 3 kHz, arteriovenous shunting was demonstrated in six. The ratio of the systolic to diastolic Doppler shift is a function of vascular impedance. This systolic/diastolic index was less than 3 in eight patients with histologic correlation. All eight had prominent vascular spaces, and the flow in such thin-walled, endothelium-lined spaces would account for the low-impedance signals. Of nine patients with systolic/diastolic indexes of 3 or less and angiographic correlation, three had marked and four had moderate tumor staining.

Prognostic significance of vascular endothelial growth factor protein levels in oral and oropharyngeal squamous cell carcinoma

PURPOSE

Vascular Endothelial Growth Factor (VEGF) promotes angiogenesis in many different tumor types. VEGF levels may affect tumor growth, metastatic potential, and response to radiotherapy. This study assesses the prognostic value of VEGF protein levels in a cohort of patients with oral and oropharyngeal squamous cell carcinomas. The relationships between clinical outcome and the covariables of tumor-node-metastasis stage, disease stage (I to IV), grade, margin status, race, sex, and age were also determined.

PATIENTS AND METHODS

Chart review identified 77 patients with oral or oropharyngeal squamous cell carcinoma treated with gross total surgical resection and postoperative radiation between 1981 and 1992. Sufficient follow-up data and tumor tissue were available in 56 patients (73%). VEGF protein levels were determined using immunohistochemistry. The association between VEGF status, covariables, and outcome was assessed in a bivariate and multivariate model using two-sided statistical tests.

RESULTS

Twenty-three tumors (41%) were positive for VEGF expression. VEGF-positive tumors were more likely to recur locally (relative risk [RR] = 3.08; 95% confidence interval [CI], 1.03 to 9.24) and distantly (RR = 4.62; 95% CI, 1.41 to 15.10). In bivariate analysis, VEGF positivity was the most significant predictor of poor disease-free survival (RR = 2.66; 95% CI, 1.27 to 5.56) and overall survival (RR = 3.21; 95% CI, 1.63 to 6.32). In multivariate analysis, VEGF positivity was the most significant predictor of poor disease-free survival (RR = 2.75; 95% CI, 1.30 to 5.79) and overall survival (RR = 3.53; 95% CI, 1.75 to 7.13).

CONCLUSION

In this cohort, VEGF positivity was the most significant predictor of poor prognosis. VEGF status may prove to be an important prognostic factor in head and neck cancer.

Comparison of rebiopsy rates after stereotactic core needle biopsy of the breast with 11-gauge vacuum suction probe versus 14-gauge needle and automatic gun

OBJECTIVE

The 11-gauge vacuum suction probe is an alternative to the 14-gauge needle and automatic gun for performing stereotactic core needle biopsies. This study compares rebiopsy rates after stereotactic core needle biopsies that were performed with the two methods. The study also assesses the outcomes of those repeat biopsies.

MATERIALS AND METHODS

Five hundred ninety-two stereotactic core needle biopsies using a 14-gauge needle and automatic gun and 354 using an 11-gauge vacuum suction probe were performed consecutively. Excluding malignancies, the number of cases requiring rebiopsy and the reasons for rebiopsy were determined for each group. The histologic diagnoses of the repeat biopsies were assessed.

RESULTS

The rebiopsy rate was significantly lower with the 11-gauge vacuum suction probe (9.0%) than with the 14-gauge needle and automatic gun (14.9%) (p = .013). Significant reductions were found in cases of insufficient sampling (probe, 1.7%; needle, 4.4%; p = .042) and mammographic-pathologic discrepancy (probe, 0.8%; needle, 3.4%; p = .026). The rebiopsy rate for masses was 6.1% with the vacuum probe versus 10.7% with the 14-gauge needle (p = .12) and for calcifications was 11.6% with the vacuum probe versus 23.7% with the 14-gauge needle (p = .003). After rebiopsy, the percentage of cases in which malignancy was found was 18.5% with the vacuum probe versus 13.7% with the 14-gauge needle. On rebiopsy, the percentage of malignancies found in each category were atypical hyperplasia: probe 26.7%, needle 20.0%; insufficient sample: probe 0%, needle 9.5%; pathologist recommendation: probe 50.0%, needle 12.5%; and lobular carcinoma in situ: probe 0%, needle 100%.

CONCLUSION

Use of the 11-gauge vacuum-assisted device significantly decreases but does not eliminate the need for rebiopsy after stereotactic core needle biopsy. The rebiopsy rate for calcifications was significantly reduced by using the vacuum suction probe rather than the 14-gauge needle; however, the rate for masses was reduced only slightly. On rebiopsy, malignancies were found in both groups.

Assessing the quality of health research from an Indigenous perspective: the Aboriginal and Torres Strait Islander quality appraisal tool

BACKGROUND

The lack of attention to Indigenous epistemologies and, more broadly, Indigenous values in primary research, is mirrored in the standardised critical appraisal tools used to guide evidence-based practice and systematic reviews and meta-syntheses. These critical appraisal tools offer no guidance on how validity or contextual relevance should be assessed for Indigenous populations and cultural contexts. Failure to tailor the research questions, design, analysis, dissemination and knowledge translation to capture understandings that are specific to Indigenous peoples results in research of limited acceptability and benefit and potentially harms Indigenous peoples. A specific Aboriginal and Torres Strait Islander Quality Appraisal Tool is needed to address this gap.

METHOD

The Aboriginal and Torres Strait Islander Quality Appraisal Tool (QAT) was developed using a modified Nominal Group and Delphi Techniques and the tool's validity, reliability, and feasibility were assessed over three stages of independent piloting. National and international research guidelines were used as points of reference. Piloting of the Aboriginal and Torres Strait Islander QAT with Aboriginal and Torres Strait Islander and non-Indigenous experts led to refinement of the tool.

RESULTS

The Aboriginal and Torres Strait Islander QAT consists of 14 questions that assess the quality of health research from an Aboriginal and Torres Strait Islander perspective. The questions encompass setting appropriate research questions; community engagement and consultation; research leadership and governance; community protocols; intellectual and cultural property rights; the collection and management of research material; Indigenous research paradigms; a strength-based approach to research; the translation of findings into policy and practice; benefits to participants and communities involved; and capacity strengthening and two-way learning. Outcomes from the assessment of the tool's validity, reliability, and feasibility were overall positive.

CONCLUSION

This is the first tool to appraise research quality from the perspective of Indigenous peoples. Through the uptake of the Aboriginal and Torres Strait Islander QAT we hope to improve the quality and transparency of research with Aboriginal and Torres Strait Islander peoples, with the potential for greater improvements in Aboriginal and Torres Strait Islander health and wellbeing.

A clinical and histopathologic analysis of the results of conservation surgery and radiation therapy in stage I and II breast carcinoma

One hundred eighty women with clinical Stage I or II operable breast carcinoma were treated by radiotherapy following local tumor excision at Yale-New Haven Hospital through 1980. With a median follow-up time of 6.9 years, the actuarial 5-year overall and disease-free survival rates were 82% and 78%, respectively. The 5-year actuarial breast-recurrence-free survival rate was 92%. Several clinical-histopathologic features and treatment parameters were assessed for their significance as predictors of local breast failure or distant relapse. Cox lifetable regression analysis showed that patients with clinical Stage II carcinomas had significantly worse overall and relapse-free survival rates, but clinical stage alone had no effect on the rate of breast recurrence. Furthermore, a decrease in overall and disease-free survival was evident when necrosis was present in the tumor or when patients had an infiltrating lobular carcinoma. Breast recurrence-free survival was also influenced adversely by the presence of these two tumor features, especially when either tumor necrosis or infiltrating lobular carcinoma was found in conjunction with clinical Stage II lesions. Other histologic features such as grade, vascular invasion, perineural invasion, or the presence of an intraductal component of carcinoma did not affect outcome, nor did the treatment techniques employed appear to have a differential effect.

Single cell analysis of cytokine gene coexpression during CD4+ T-cell phenotype development

CD4+ T cells from alpha beta-T-cell receptor transgenic mice were analyzed for coexpression of cytokine mRNAs during phenotype development using a double-label in situ hybridization technique. T cells that produced cytokines in the primary response were a fraction of the activated population, and only a minority of the cytokine-positive cells coexpressed two cytokines. In secondary responses, frequencies of double-positive cells increased, although they remained a minority of the total. Of the cytokine pairs examined, interleukin (IL)-4 and IL-5 were the most frequently coexpressed. IL-4 and interferon gamma showed the greatest tendency toward segregation of expression, being rarely coexpressed after the primary stimulation. These data indicate that there is significant heterogeneity of cytokine gene expression by individual CD4+ T cells during early antigenic responses. Coexpression of any pairs of cytokines, much less Th1 and Th2 cytokines, is generally the exception. The Th0 phenotype is a population phenotype rather than an individual cell phenotype.

Intracystic papillary carcinoma of the breast. After mastectomy, radiotherapy or excisional biopsy alone

Intracystic papillary carcinoma of the breast (IPC) was distinguished from the more common papillary intraductal carcinoma (DCIS) and infiltrating duct carcinoma with a papillary pattern. IPC was defined as a solitary tumor with a pattern recognizable as carcinoma which is confined to a dilated duct. A series of 41 such cases was collected from three institutions. Twenty-nine patients underwent mastectomy; 11 of them had axillary dissections. None of these patients had metastatic disease in the axillary lymph nodes or recurrence in the follow-up period which averaged five years. Eleven patients did not have mastectomy or radiotherapy. Eight of these patients (followed for an average of ten years) had no recurrence. The only patients who developed invasive carcinoma were those with DCIS as well as IPC in the excisional biopsy. The data suggest that IPC is much more likely to be cured by local treatment than is IPC accompanied by DCIS.

Carcinoma in situ of the breast

A series of 87 cases of carcinoma in situ of the breast was reviewed. IN 49 CASes in which lobular carcinoma in situ was shown on biopsy, three patients were found to have invasive carcinoma in the subsequently done mastectomy. All three of these cases were in a group of 14 patients shown in have bilateral lobular carcinoma in situ on biopsy. In a group of 38 patients with intraductal carcinoma on biopsy, seven were found to have invasive carcinoma in the mastectomy that was subsequently done. Lymph node metastases were found in one patient in the lobular group and four patients in the intraductal group. Three patients in the intraductal group died of cancer. None in the lobular group has died of cancer.

Intraductal papillary tumors of the breast: a study of 78 cases

Seventy-eight intraductal papillary tumors of the breast were followed. The 14 papillary carcinomas were all treated by mastectomy. Metastases did not occur. In 64 patients with papillomas, six developed carcinoma--two in situ and four invasive. The incidence of cancer was higher in patients with multiple papillomas and with papillomatosis. The current experience (1949-1967) is discussed relative to the previous experience at the same institution from 1895 to 1941.

Ductal carcinoma in situ diagnosed with stereotactic core needle biopsy: can invasion be predicted?

PURPOSE

To determine whether mammographic or histologic features can be used to predict which cases diagnosed as ductal carcinoma in situ (DCIS) without invasion by means of stereotactic core needle biopsy (SCNB) will have invasive disease at surgery.

MATERIALS AND METHODS

From July 1992 to March 1999, DCIS without invasion was diagnosed by means of SCNB in 59 patients. Seventeen (29%) were found to have invasive disease after surgery. The underestimation rate for SCNB was compared with that obtained by means of open surgical biopsy. Mammographic and histologic features of cases with and those without invasion were compared.

RESULTS

All patients had calcifications on mammograms. There was no significant difference (P: =.26) between the underestimation rate for SCNB with the 11-gauge vacuum-assisted device and that for open surgical biopsy. No statistically significant differences between cases with and those without invasion were seen in patient age, mean number of core specimens, level of suspicion, size of lesion, distribution and morphology of the calcifications, presence of an associated mass or density, subtype of DCIS, nuclear grade, or presence of necrosis or desmoplasia.

CONCLUSION

Mammographic and histologic features cannot be used reliably to predict cases that are underestimated with SCNB. However, SCNB with the 11-gauge vacuum-assisted device was as reliable as open surgical biopsy for diagnosing DCIS without invasion.

Underestimation of breast cancer with II-gauge vacuum suction biopsy

OBJECTIVE

The purpose of this study was to determine the mammographic and histologic features of cancerous lesions underestimated using 11-gauge vacuum suction biopsy.

MATERIALS AND METHODS

Retrospective review of 11-gauge vacuum suction biopsy was performed to identify lesions diagnosed as atypical ductal hyperplasia or carcinoma. The histology of the core and surgical specimens was compared. Of 158 cases of cancer, underestimation occurred in 15 (9.5%). The mammographic and histologic features were assessed.

RESULTS

Of 15 underestimated cases, six were atypical ductal hyperplasia that proved to be cancer (5 ductal carcinoma in situ and 1 invasive) and nine were ductal carcinoma in situ that proved to have invasion. The underestimation rate for calcifications was 16.3% (14/86) and for masses was 1.6% (1/64) (p = 0.007). Most (5/6) underestimated atypical ductal hyperplasia cases were reported as "markedly atypical," and four of nine underestimated ductal carcinoma in situ cases were reported as "possible invasion." No significant difference was seen in the number of core specimens obtained or the sizes of the lesions for underestimated cases versus accurately diagnosed cases. The percentage of calcifications retrieved was significantly different (p = 0.017). No underestimations were found among cases in which the entire mammographic lesion was removed at vacuum suction biopsy.

CONCLUSION

The cancer underestimation rate with vacuum suction biopsy was 9.5%. The underestimation rate for calcifications (16.3%) was significantly higher than that for masses (1.6%) (p = 0.007). The percentage of the lesion removed was an important factor in reducing underestimation, as reflected by the percentage of calcifications retrieved and the instances of complete resolution of the lesion seen on mammography.

Histopathological features of hepatitis C in renal transplant candidates [see comment]

BACKGROUND

Although hepatitis C virus (HCV) infection is common in renal transplant candidates, its clinical significance remains unclear in this population. Little detailed information is available about the histological severity of HCV infection in these patients. We evaluated the liver biopsy features of chronic HCV in a large population of renal transplant candidates and investigated associations between histopathological changes and host- and virus-related factors.

METHODS

Thirty-seven patients seropositive for anti-HCV with chronic renal failure (CRF) referred to UCLA Medical Center for kidney or kidney/liver transplantation during the period 1992-1997 were included. HCV genotype and viral load were measured. A multivariate analysis by logistic regression model was performed: age, gender, race, HCV load and genotype, CRF level, aspartate and alanine aminotransferase activity, duration of HCV infection, underlying nephropathy, and alcohol abuse were independent variables; liver histology score was assumed a dependent variable.

RESULTS

Liver disease was present in all HCV-infected patients. Logistic regression analysis revealed that histological damage was (P = 0.0017) independently associated with the CRF level; the severity of liver disease, as shown by univariate analysis, being significantly higher in CRF patients not requiring dialysis than among dialysis population. All patients on dialysis showed mild or moderate necroinflammatory activity; the majority (22/28 = 79%) of these individuals had fibrosis, three (3/28 = 11%) dialysis patients had established cirrhosis. Thirty-one (84%) of 37 patients were tested by polymerase chain reaction, 25 (81%) patients had detectable HCV RNA in serum, the mean HCV load among viremic patients was 10.9x10(5) copies/ ml. The most frequent HCV genotypes were la (8/24 = 33%) and 1b (7/24 = 29%), followed by genotype 2b (3/24 = 12%).

CONCLUSIONS

Pathological changes on liver biopsy were observed in all HCV-infected patients awaiting renal transplantation. The severity of histologic damage observed on liver biopsy was less in dialysis than predialysis CRF patients. All dialysis patients had mild or moderate necroinflammatory activity; fibrosis was frequent with 11% of them having cirrhosis. The HCV viral load was rather low; no relationship between liver histology changes and virological features of HCV or aminotransferase activity was apparent. Further studies with repeat liver biopsies after kidney transplantation to observe the evolution of HCV-related liver disease after immunosuppressive therapy are indicated. We suggest including liver biopsy in the evaluation of the HCV-infected renal transplant candidate.

Breast carcinoma in situ: risk factors and screening patterns

BACKGROUND

Risk factors associated with invasive breast cancer are well documented, but those associated with breast carcinoma in situ are not well defined.

METHODS

We conducted a population-based, case-control study among female residents of Connecticut to identify risk factors for breast carcinoma in situ. Case patients, diagnosed with ductal carcinoma in situ (DCIS) (n = 875) or lobular carcinoma in situ (LCIS) (n = 123), were matched by 5-year age groups with control subjects (n = 999). Case patients were diagnosed between September 15, 1994, through March 14, 1998, and all subjects were between the ages of 20 and 79 years. Information on risk factors and cancer-screening history was collected by telephone interviews. Conditional logistic regression was used to determine odds ratios (ORs) for the association of these factors with the risk of DCIS and LCIS.

RESULTS

Case patients with DCIS were more likely than control subjects to report a family history of breast cancer (OR = 1.48; 95% confidence interval [CI] = 1.19 to 1.85) or previous breast biopsy (OR = 3.56; 95% CI = 2.86 to 4.43). They also had fewer full-term pregnancies (OR = 0.86; 95% CI = 0.80 to 0.93) and were older at first full-term pregnancy (OR for being 20-29 years old relative to being <20 years old = 1.68; 95% CI = 1.17 to 2.43) and at menopause (OR for being > or =55 years old relative to being <45 years old = 1.71; 95% CI = 1.05 to 2.77). DCIS case patients were more likely than control subjects to have had a mammographic examination (OR = 2.46; 95% CI = 1.78 to 3.40) or an annual clinical breast examination (OR = 1.83; 95% CI = 1.48 to 2.26). DCIS patients and control subjects did not differ with respect to oral contraceptive use, hormone replacement therapy, alcohol consumption or smoking history, or breast self-examination. Associations for LCIS were similar.

CONCLUSIONS

The risk factors associated with DCIS and LCIS are similar to those associated with invasive breast cancer. Diagnosis of DCIS is associated with increased mammography screening.

Immunohistochemical evaluation of pleural mesothelioma and pulmonary adenocarcinoma. A bi-institutional study of 47 cases

Pleural mesotheliomas and peripheral pulmonary adenocarcinomas were evaluated by immunohistochemistry at two institutions (Yale University School of Medicine and the City of Hope National Medical Center). Twenty-three mesotheliomas, 11 with ultrastructural verification, and 24 pulmonary adenocarcinomas were studied. Antikeratin, anticarcinoembryonic antigen, anti-human milk fat globule related antigen, MC-1, B72.3, and Leu M-1 antibodies were employed. The immunohistochemistry of each case prepared at one institution was reviewed at the other. As groups, the two tumor types were distinguishable using this antibody panel. Essentially, mesotheliomas were keratin positive only. The adenocarcinomas were positive for CEA, MFG, B72.3, and Leu M-1. However, there were some ambiguities presented by the immunohistochemistry. The higher molecular weight keratins were found in most but not all mesotheliomas and in only a few adenocarcinomas. Lower molecular weight keratins were positive not only in all the mesotheliomas, but also in nearly all the adenocarcinomas, but also in a tumor determined by electron microscopy to be mesothelioma. Preabsorption of CEA decreased the sensitivity for adenocarcinoma, but did not change the positivity of the putative mesothelioma. B72.3 and Leu M-1 were specific for adenocarcinoma, but were found in only half of them. The MFG was apparently specific for adenocarcinoma, but the findings were difficult to interpret. At the level of individual cases, greater sensitivity of separation can be achieved by combining the results of two or more antibodies, but the lack of a detectable specific antigen in mesothelioma continues to make some cases difficult to evaluate by immunohistochemistry alone.

Vasopressin gene expression in the rodent hypothalamus: transcriptional and posttranscriptional responses to physiological stimulation

The neuropeptide vasopressin (VP) is expressed in the supraoptic nucleus, a discrete group of neurons in the hypothalamus that respond to osmotic stimuli. In the rat the pattern of expression of VP mRNA changes in two ways as a consequence of the physiological stimulation of these neurons. Firstly, there is an accumulation of VP mRNA, and secondly, the poly(A) tail of the VP mRNA increases in length. We asked whether the increase in VP mRNA level is a consequence of transcriptional or posttranscriptional mechanisms. We present evidence from nuclear run-on assays that increases in the transcription of the rat VP gene are sufficient to account for the accumulation of VP mRNA observed in chronically stimulated animals. However, we note that in acutely stimulated animals there are rapid and relatively large increases in VP gene transcription that do not correlate with increases in the VP mRNA level, but coincide with the appearance of a homogeneous class of VP mRNAs with elongated poly(A) tails. We suggest that immediately after the onset of an acute osmotic stimulus, there is a rapid destruction of preexisting VP mRNAs and their replacement with new transcripts bearing longer poly(A) tails. We have also addressed the question of the function of the elongated VP mRNA poly(A) tail. It is unlikely that the poly(A) tail extension is involved in RNA stability; the transcriptional changes observed are sufficient to account for the increase in VP mRNA level, and we show that in the mouse similar increases in VP mRNA level are observed without concomitant changes in poly(A) tail length. We did not observe a change in the polysome distribution of the VP mRNA after osmotic stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Perceptions of academic vulnerability associated with personal illness: a study of 1,027 students at nine medical schools. Collaborative Research Group on Medical Student Health

About one quarter of the more than 69,000 medical students in this country suffer symptoms of mental illness, including 7% to 18% with substance use disorders. Subjective distress and physical health needs of medical students are also common and have been linked to training stresses. This first large-scale study of medical student health care examined students' physical and mental health concerns and their perceptions of academic vulnerability associated with personal illness. A 7-page, confidential written survey was given to 1,964 students at nine US medical schools in 1996 and 1997. A total of 1,027 students participated (52% response rate). Nearly all (90%) reported needing care for various health concerns, including 47% having at least one mental health or substance-related health issue. A majority of students expressed a preference for health care outside their training institution, largely due to confidentiality concerns, and 90% preferred health insurance allowing off-site care. Students expressed varying levels of concern about academic jeopardy in association with personal illness, with physical health problems such as arthritis causing the least concern and alcohol and drug abuse triggering the most concern. Consistent differences were detected in these views based on respondent's gender, training level, and institution. Most medical students perceive the need for personal health care. Nevertheless, fear of academic reprisal may prevent medical students from seeking necessary care for their health problems during training. This phenomenon may be linked in important but poorly recognized ways to emerging illness and to impairment among medical students and physicians. Women, minority, and clinical students appear more sensitive to the connection between health and academic vulnerability. Constructive implications for medical school curricula, policies, and health care services are discussed.

Scar cancers of the lung: origin and significance

The relation between scarring and the development of pulmonary neoplasia has been a topic of interest for some time. One current concept suggests that the scar is a predisposing factor in the development of a cancer. In contrast, the scar or desmoplasia observed in breast, stomach, pancreatic, and colonic neoplasms is presumed to be a host response to the neoplasm. In the present study type-specific collagen antibodies were used in an immunofluorescence assay. By taking advantage of the collagen heterogeneity present in the lung and the changes in relative amounts of different collagen types during the fibrotic response, the fibrotic processes in tumorous and nontumorous areas of individual specimens were assessed qualitatively. The findings are consistent with the notion that the scar or desmoplasia in and around pulmonary tumors is not "mature" and inactive but rather represents an active, ongoing process, as evidenced by the continued presence of type III collagen. In contrast, areas of fibrosed lung parenchyma at some distance from the neoplasm revealed a mature, late stage of the fibrotic process, as evidenced by a decrease in type III and increases in types I and V collagen. Thus, the findings support the notion that the scarring associated with pulmonary neoplasia appears to be a host response to the tumor.

Local recurrence versus new primary: clinical analysis of 82 breast relapses and potential applications for genetic fingerprinting

PURPOSE

The purpose of this study was to perform a detailed clinical pathological analysis of breast relapses in patients treated with conservative surgery and radiation therapy in an effort to classify those relapses as true local recurrences or second primary tumors, and to assess the prognostic and therapeutic implications of such a classification system.

METHODS AND MATERIALS

Of 990 patients treated with conservative surgery and radiation therapy at our facilities prior to December 1987, 82 patients have experienced a relapse in the conservatively treated breast as the primary site of failure. Patients were classified as having new primary tumors if they fulfilled any one of the following criteria: a) breast relapse occurring at a site distinctly removed from the original tumor; b) histology of the breast relapse compared with the original tumor consistent with a new primary; or c) DNA flow cytometry converting from an aneuploid primary to a diploid relapse.

RESULTS

As of 2/92, with a median follow-up of 5.4 years from the time of breast relapse, the overall 5-year survival rate following breast relapse was 55%. Forty-seven patients were classified as true recurrences and 33 patients were classified as new primaries. Patients classified as true recurrences had a shorter median time to breast relapse than patients classified as new primaries (3.16 years vs. 5.42 years, p < .05) and an inferior post breast recurrence survival rate compared to patients classified as new primaries (36% vs. 89%, p < .05). Residual disease outside of the recurrent tumor bed was also noted to be more frequent in patients classified as true recurrences compared to patients classified as new primaries (48% vs. 16%, p < .05).

CONCLUSION

Based on the clinical and pathological criteria outlined, it appears that a significant portion of patients experiencing a relapse in the conservatively treated breast may have new primary tumors as opposed to true local relapses. Distinction between a true recurrence and a new primary tumor may have significant prognostic implications. Uncertainties associated with the clinical and pathological criteria are presented and further investigations with genetic fingerprinting techniques to establish the clonality of breast relapses are presented and discussed.